Ignition system for internalcombustion engines



M. MALLORY 2,365,768 IGNITION SYSTEM FOR INTERNAL-COMBUSTION ENGINES Dec. 26, 1944.

Filed 00%. 30, 1943 INVENTOR. Mar/b0 Mal/any ,BY fi/ww 1444M ma [J ?aiented Dec. 26, 1944' UNITED sTATEs PATENT OFFICE IGNITION SYSTEM FOR INTERNAL- COMBUSTION ENGDNES Marion Mallory, Detroit, Mich. Application October 30, 1943, Serial No. 508,300

7 Claims. (Cl. 123-417) This invention relates to an ignition system for an internal combustion engine and more par- It is the object of this invention to produce a manifold pressure timed ignition system in which the spark will be advanced when the car is decelerating with the clutch engaged and the throttle closed.

it is also an object oi this-invention to produce a' manifold pressure timed ignition system in which the vacuum utilized in advancing or retarding the spark is more precisely controlled or varied in accordance with the timing best suited tor the engine in view of the conditions under which it is operating.

Fig. l is a view partly in section showing my pressure timed ignition system.

Fig. 2 is a section along the line 2 -2 of Fig. 1.

Fig. 3 is a section along the line 33-3 at Fig. 1.

The carburetor l, adapted for attachment to an internal combustion engine, is provided'with an intake passageway t having an air inlet end designated 9 and a iuel mixture outlet it through which the fuel mixture is adapted to pass into the engine intake manifold.

The passageway t includes the venturi ii and, for purposes oi description rather than by way of limitation, a booster venturi ii is positioned within the mainventurl ll. usual butterfly throttle valve mounted within the passageway t on shaft 3 which is swung open and closed by the rod it and crank it. The fuel float bowl is designated it. Fuel is drawn from the float bowl through passageway ll into the mining chamber. A v

A conventional timing mechanism is shown consisting of the usual 'otatable cam it which operates the electrical circuit breaker l9 mounted on plate which can be rotated clockwise to advance the spark and counterclockwise to retard the spark. A suction device ii is used for advancing and retarding the spark. The suction device comprises a flexible diaphragm 22 backed up by a compression coil spring 23. The diaphragm is mounted in housing 24 which is connected to the carburetor by conduit 25. The diaphragm is connected to plate 20 by rod 28, one end of which is pivotally connected as at '21 to the plate 20 and the other end of which is fixed to the diaphragm. The wall 28 of the it designates the housing is perforated so that the diaphragm is subjected on the outside to atmospheric pressure whereas on thelnside of housing it the diaphragm is subjected through line 25 and passageway 29, orifices to, 3i, passageway 32 and orifice 33 to certain pressure conditions obtaining in and created by the intake passageway ll, as described below.

Passageway it, between orifice 3i and the point at which passageway 32 communicates with passageway 2? is provided with a ball check valve til held against its seat by a compression spring 8%. Compression spring 35 is strong enough to hold ball check til against its seat unless the car is decelerating with the throttle closed and the clutch engaged so that the car is driving the engine. Under such con ditions the vacuum in the manifold on the em gine side of throttle it will go higher than the manifold vacuum at idle and this vacuum will hold the check valve 3d away from its seat, thereby connecting orifice it with conduits 2t and 25 to advance the spark. This is important because the spark should be advanced when the car is overrunning the engine with the clutch engaged and the throttle closed, which produces a very high vacuum in the manifold.

Orifice tt'is positioned so that it falls on the outlet or engine side oi throttle valve it as soon as the throttle valve is partially opened from idle position.

Passageway it, between orifice t0 and conduit it, is provided with a variable air bleed in the form of a piston valve lt mounted in bore ti v 32, 29 and 25 and plays the role of a variable air bleed to the suction device from the Venturi restricts the amount that the suction device can be air bled through orifice 30. If the throttle is opened to about half way or more, the vacuum will drop in passageways 25 and 29 on the manifold or engine side of valve 40, thus permitting spring 43 to raise piston valve 40 ofi its seat 42 to bleed additional air into the suction device through orifice 30 and by the fiat side 41 of valv 40 in addition to the air that bleeds through passageway 44 in the valve 40. Thus, it is evident from the above that valve 4!) acts as a variable air bleed to the suction device.

I claim:

1. An ignition system for an internal combustion engine comprising an ignition timer, an intake passageway, a. throttle valve in said intake passageway, a suction controlled device connected to said timer ior advancing and retarding the spark, an orifice in the intake passageway positioned at all times on the atmosphere side of the throttle valve, a passageway connecting said orifice with the suction controlled device, a second orifice communicating with the engine side of the intake passageway when the throttle valve is in partly opened position, a second passageway connecting said second mentioned orifice with said suction device, and variable air bleed means positioned in the first mentioned passageway responding to vacuum conditions in the intake passageway for varying the communication between the first mentioned orifice and the suction device.

2. An ignition system for an internal combustion engine comprising an ignition timer, an intake passageway, a throttle valve in said intake passageway, a suction controlled device connected to said timer for advancing and retarding the spark, an orifice in the intake passageway posttioned at all times on the atmosphere side of the throttle valve, a conduit connecting the suction device with said orifice, a second conduit for applying suction to the suction device from the engine side of the throttle valve in partly opened position whereby the first orificeacts as an air bleed when the throttle valve is in partly opened position, and variable air bleed mechanism between the orifice and the suction device responding to a high vacuum in the intake passageway on the engine side of the throttle valve to decrease the air bleed of the suction device through the first mentioned orifice and responding to a decrease in the manifold vacuum such as occurs when the throttle is open to increase the air bleed of the suction device through the first mentioned orifice and thereby retard the spark.

3. The combination as set forth in claim 2 wherein the variable air bleed mechanism comprises a vacuum operated valve having a fixed passageway therethrough which at all times permits communication between the first mentioned orifice and the suction device, and a second passageway which permits communication between said orifice and the suction device only when the valve is open.

4. An ignition system for an internal combustion engine for a vehicle comprising an ignition timer, an intake passageway, a throttle valve in said intake passageway, a suction controlled deviceconnected to said timer, an orifice in the intake passageway on the engine side of said throttle valve, a second orifice in said intake passageway on the atmosphere side of said throttle valve, a conduit connecting said suction device with said orifices in the intake passageway, a check valve in said conduit normally shutting 01! gauges the suction device from the first mentioned orifice on the engine side or the throttle valve, said check valve opening only in response to a high vacuum at said first orifice such as occurs when the throttle is closed and the engine is overrun by the vehicle whereby spark is advanced.

5. An ignition system for an internal combustion engine for a vehicle comprising an ignition timer, an intake passageway, a throttle valve in said passageway,.a suction controlled device connected to said timer for advancing and retarding the same, an orifice in the intake passageway on the engine side of said throttle valve, a second orifice in said intakepassageway on the atmosphere side of said throttle valve at idle position and on the engine side of said throttle valve when the same is partly open, and a third orifice in the intake passageway at all times on the atmosphere side of said throttle valve, a conduit connecting said suction device with said orifices, and a check valve in said conduit normally shutting off the suction device from the first mentioned orifice on the engine side of the throttle valve and opening in response to a high manifold vacuum at said first mentioned orifice such as occurs when the throttle is closed and the engine is overrun by the vehicle whereby the spark is advanced.

6. An ignition system for an internal combustion engine comprising an ignition timer, an intake passageway, a throttle valve in said intake passageway, a suction controlled device connected to said timer -for advancing and retarding the spark, an orifice in the intake passageway positioned at all times on the atmosphere side of the throttlevalve, a passageway connecting said ori fice with the suction controlled device, a second orifice in the intake passageway communicating with the engine side of the intake passageway when the throttle valve is in partly opened position, said second orifice communicating with the atmosphere side of the intake passageway when the throttle valve is in idle position, a second passageway connecting said second mentioned .orifice with said suction device, and variable air bleed means positioned in the first mentioned passageway responding to vacuum conditions in the intake passageway for varying the communication between the first nrentioned orifice and communicating with the engine side of the intake passageway when the throttle valve is in partly opened position, said second orifice communicating with the atmosphere side of the intake passageway when the throttle valve is in idle position, a second passageway connecting said second mentioned orifice with said suction device, and variable restricting means positioned in the first mentioned passageway responding to vacuum conditions in the intake passageway for varying the communication between the first mentioned orifice and the suction device.

MARION 'MALLORY, 

